Dr. Tsubokura's Radiation Lecture Vol.22

Author: Masaharu Tsubokura

Editors: Akihiko Ozaki M.D., Yuki Senoo

43. There are various causes of cancer

I am often asked if an exposure to high-level radiation would increase the risk of developing cancer. Before answering this question, I would like to talk about what cancer originally is.

Numerous cells which constitute our body send signals to each other, and each one of them plays its specific role according to its placement. These cells interact with one another so that our bodies are able to function as a single organism.

Malignant tumor or cancer is a situation that a part of such cells may become out of control, and start to proliferate unlimitedly, hindering essential functions of organs and other parts of bodies. In short, cancer is originally our cells.

Causes of cancer are largely categorized into those related to lifestyles, such as alcohol consumption, smoking, high salt intake, and obesity, and infectious diseases such as H. pylori and Hepatitis C. Radiation exposure is just one of many different causes of cancer.

44. What does "increased risk of cancer" mean?

A variety of things including lifestyle, infectious diseases, and high-level radiation exposure can cause cancer. Particularly, smoking is one of the most well-known causes of lung cancer.

A complicated thing is that a statement that smoking increases a risk (possibility) of having lung cancer means that smokers are several times more likely to develop lung cancer in future than non-smokers: it does not mean that all of the smokers will develop cancer or that all of the non-smokers will never develop cancer in future.

This is the same for a case of radiation exposure: a high-level radiation exposure increases a risk of having cancer in future, but it does not mean that you will definitely have cancer after being exposed to even low level of radiation or that you will be free from illnesses as long as you are not exposed to radiation.

There is a significant difference between having an increased risk of one condition and actually having such condition.

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The Japanese version of the manuscript was originally published in Fukushima Minyu, a local newspaper in Fukushima prefecture, Japan, on October 18th ,25th 2015, and was reproduced for MRIC Global under the author's permission.